What type of filtering utilizes predetermined keywords to identify undesirable content?

The correct answer is content or keyword filtering because it specifically refers to the method of using certain predetermined keywords to identify and block undesirable content, such as inappropriate or irrelevant material. This type of filtering allows organizations or individuals to set criteria for what constitutes undesirable content, making it a targeted approach to content moderation. By specifying keywords, users can effectively screen out unwanted information, ensuring a safer or more relevant browsing experience.

In contrast, other options may involve different methodologies. Blacklisting typically refers to creating a list of known undesirable entities or addresses rather than focusing on keywords. Delay-based filtering involves temporarily holding back content until it can be reviewed, and statistical content filtering generally uses algorithms and data analysis to assess the likelihood of content being problematic based on patterns rather than specific keywords. Therefore, content or keyword filtering stands out as the most precise answer regarding the use of predetermined keywords for filtering undesirable content.